It is known that various surfactants have been found to be useful in cleaning compositions, such as shower gels, shampoos, and light duty detergents (e.g., dish detergents)--compositions in which good foamability is a prerequisite for consumer approval. The surfactants which have been used to the greatest extent in such compositions are anionic surfactants, such as alkyl sulfates, alkyl ether sulfates, sulfonates, sulfosuccinates, and sarcosinates.
Although the use of anionic surfactants in these compositions permits the attainment of desirable characteristics, including good foamability, it would be beneficial to find other surfactants which could provide equal performance at a lower cost. However, other known surfactants, such as amine oxides, betaines, and alkanolamides, are either more costly than the anionic surfactants or give poorer performance, e.g., smaller foam volume, when substituted for the anionic surfactants.
It is sometimes advantageous to use mixtures of surfactants in cleaning compositions when the surfactants can serve different functions, e.g., one serving to improve foamability and another serving to adjust viscosity. Heretofore, however, it was not thought that the use of (A) a less costly surfactant which, by itself, gives poor performance in a particular regard, e.g., foamability, in admixture with (B) a more costly surfactant which, by itself, gives good performance in the same regard, could permit the retention--or even the improvement--of the good performance of the more costly surfactant while reducing the total cost of surfactant used. The most common result of using such an admixture is to provide a performance which is intermediate to the performances of the different surfactants.